What is a Zoning System and Why Would I Want One?

Upgrading to a zoning system gives your single furnace and air conditioner the flexibility to handle multiple temperatures under one roof. The design and construction of a house makes indoor temperature variations inevitable. Since heat rises, upstairs rooms are usually naturally warmer. Meanwhile, living spaces downstairs with exterior walls facing away from the sun may be simultaneously chilly. Continuously adjusting the thermostat to maintain a comfortable compromise throughout the whole house often means your HVAC system cycles on and off excessively, adding to wear and tear and decreasing system energy efficiency.

A zoning system divides your home into two or more distinct temperature zones controlled by independent thermostats, without the expense of installing a second furnace and air conditioner. Zoning also allows you to withhold heating and cooling from parts of the house that are unoccupied at certain times of day while still maintaining comfortable temperatures in occupied areas. Studies have shown that energy savings achieved by upgrading to a zoning system range from 15 percent to 29 percent.

Here’s how zoning works in a typical two-zone configuration:

Motorized dampers are installed in your HVAC ductwork to control the flow of heated or cooled air into pre-determined zones in the house. The dampers are operated by a central controller that receives signals from independent thermostats located in each zone.

In the default position with the system cycled off, all dampers are open. If the thermostat in Zone 1 signals for heat or cooling, the controller closes the appropriate dampers to Zone 2 and conditioned air flows to Zone 1 only. If the Zone 2 thermostat subsequently signals the controller, dampers leading to that zone open as well.

As the desired temperature setting at each dedicated thermostat is achieved, dampers leading to that zone are closed and heating or cooling ceases to flow into those rooms. When both zones are at the desired temperature, the furnace or A/C cycles off and all dampers in the system return to the default open position.